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AC Fully Charged, but temp won't get below 65 deg....???

7385 Views 31 Replies 9 Participants Last post by  marvinstockman
Hey guys!

I've got an 03 3.8 with Climate Control, we replaced the compressor last year but it has never really gotten "Cold"... it does get "Cool" when you're running down the highway, but I still have to have it on high the whole time.... even with all three zones on "Lo".... I tested the temp today and the lowest it got down to was like 71 deg...

Things I know..

Charge is good with no leaks
I have always kept the cabin filter changed and in good shape
I've hosed down the condenser coils the best I could with out removing anything
Fans are on
tube in engine bay is cool or borderline cold.. but not "COLD" like it should be - Ice cold or frosted up
Rear unit is producing the same or similar discharge air temps

I haven't checked the high side, thinking about picking up a cheap set of gauges from harbor freight to test.
I don't think the compressor is short cycling or anything but haven't had a chance to check that our for sure yet.

Didn't know if somebody has had similar issues and if so, what the fix or problem was?

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What is the temp coming out of the vents? Also, you do need a set of inexpensive gauges to proceed, and the first step would be to check static pressures on a cold engine, which means nothing running.

For example, if the engine and car are at 90F, the static high and low side pressure is probably around 100psi.

My guess is that you're just low on R134.
Welcome to the forum Werner1
What marvinstockman said.

You say you replaced the compressor last year. How about the condenser and the accumulator drier? The condenser's now a day are not able to be cleaned efficiently and it is recommended they are replaced, especially after a compressor failure as the condenser catches all the debris from a compressor failure. The condenser also becomes less efficient over the years as it becomes clogged, especially if a full vacuum was not pulled and corrosion forms within the system.

Remember, an air conditioning system only has a certain degree of efficiency. What is the outside temperature?

The system can only obtain so many degree difference. Perhaps it may not be operating inefficiently, rather you are just expecting the temperature to be colder than the law of physics will allow.

Check your state of charge. Then return and let us know what you find.
Remember, overcharging a system also can make it less efficient (and may damage the compressor).

Again, please return and tell us how you get your system repaired and what you find.
Welcome to the Mopar Minivan Garage!
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What is the temp coming out of the vents? Also, you do need a set of inexpensive gauges to proceed, and the first step would be to check static pressures on a cold engine, which means nothing running.

For example, if the engine and car are at 90F, the static high and low side pressure is probably around 100psi.

My guess is that you're just low on R134.
lowest discharge air temp I have been able to get out of it at the vents is 65 deg. ... yesterday it was like 71 deg.

Ironically today on the way to work it was blowing out pretty cool,.. but it wasn't that hot out either (I didn't have my tester with me this morning.. )

I'll be picking up a set of gauges tonight and I'll do a static test tomorrow morning after everything has been sitting over night.

The system/compressor was installed late last summer and was vac'd down and proper charge applied along with die.... results are still the same as they were then - cool,. not cold. I'd be hard pressed to believe that it's not charged since I've checked it my self and adding an additional shot of 134,.. and also removing a bit as well just testing purposes ... but stranger things have happened that's for sure! :D
I'll be picking up a set of gauges tonight and I'll do a static test tomorrow morning after everything has been sitting over night.
\Be careful not to introduce air into the system with your gauge set. Air is non condensable.
I purge the hoses of air with refrigerant from the tank(or a can, or even some from the system) prior to opening valves or connection. When you are complete you may recover the refrigerant in the gauges/hoses back into the system low pressure side.
take a look into the blend door and make sure it is moving and not stuck, its a door that mixes the cold air and hot air. Sorry I do not know to get to it on the van
Do not use this chart for PSI readings, only for Air Temp coming out of vents

This is the chart I use for static pressures

This is the pressure chart to use
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Welcome to the Forum.

Clutch working?

Without static and operating pressure measurements, can't say much. Seems you have done all the right things.
Ok guys... sorry been a crazy couple of days... but I was able to pick up some 134a quick couple adapters for my regular gauge set at home,.. so I went out yesterday morning before the van had been started or anything and hooked up the gauges...

So my static looks like: 82 Low / 82 High

Running Pressure: 38 Low / 178 High

Outside air temp was around 80 Deg. Humidity was a little high..

I Have a nice temp meter w/thermocouplers that we use at work - I tried to attach it to the "Cold" pipe in the engine compartment that is usually really cold, I didn't have my pipe clamp sensor with me, so I tried to tape it on the pipe that was already sweating,. and the lowest reading I got there was in the 60's

Clutch - I know I should have checked how it was cycling pretty much first, but you can't see it from the top and you have to jack up the vehicle and remove the inner/lower/front fender shroud to see the AC compressor.... didn't really have time for that yesterday morning.. I was trying to listen and watch the gauges,.. but honestly it wasn't obvious at all when the compressor was running or not... must be a super quiet cluch (?) haha!

fabricGATOR - I totally understand about the whole "Degree of Efficiency" thing... but even when it's not that hot out,. low 80's, it still doesn't pump out air temps lower than the 60's .... should be chuckin' ice cubes. :p

Thanks for all of suggestion and help thus far,.. I'm sure it's just a matter of time till we get to the bottom of this!

I must say I have been pleasantly surprised at the quantity and the quality of the responses on here - when I first stumbled upon this forum I really didn't think there'd be much "activity" .... but that's not the case!

Here's some pics of the gauge readings..

Analog watch Watch
Tire Automotive tire Tool accessory
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Freggie seems to bring experience to the discussion. The blend door... yes.

Perhaps you could use a c-clamp and a few cuts of wood, to clamp a hot water hose, gently closed, going to the heater core and see if that makes a difference in the cabin... The heater water exits the engine block on my 3.8 behind where the large upper radiator hose is connected to the engine.

There is also a procedure that puts your climate controls through a calibration and check mode. Something about holding two button when turning it on. JeepMan? (not your cue for a fluid film plug, I'll cue you later for that...)
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Yeah I can double check the heater/blend door thing,.. I've done the Climate control procedure....twice... no change. Even when running the AC before the engine warms up there is no noticeable temp drop in the discharge air... ?
maybe the evaporator is just full of gunk

is it possible to inspect it visually from where the blower motor housing is?
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High side is too low, should be in the 200's @ 80 F. Also when recharging some times the High side will go in the 350 to 400 range and drop down into the 200's when fans are running.
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Sorry guys,.. crazy 4th of July weekend!,.. on the bright side I did get my V65 Magna plated and rode it around a while! :D

Back to the T&C AC Problem..

I didn't have a chance to check out anything else on it yet..... next up on the list is:

1 - Visually inspect Clutch during operation
2 - Visually inspect Evaporator coil
3 - Physically block off Heater lines
4 - Check blend door operation/position

IF all items above are "OK"... would that indicate a defective (Open) expansion valve,.. and/or faulty compressor - doesn't seem like it's not compressing enough.. (???)
Easy way to check if clutch is working is to pull the relay and put it back in and listen if the clutch "clicks" on or clicks off when you pull the relay.

But... your clutch is working because the low/high pressures are in range, just a bit low....

Evaporator coil should be okay - no gunk because you change the the filter regularly.

Why block off the heater lines?

To do list:
check blend door
add r134a, then bleed if necessary to right static pressure
maybe check condenser and see if anything is blocking the airflow

bad expansion valve and high and low pressures would be off, they are in range, just low. too little r134a and it would not 'cool' as good, same with too much r134a
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maybe the evaporator is just full of gunk

is it possible to inspect it visually from where the blower motor housing is?
Perhaps the condenser is internally full of crap and not working efficiently.
How/why did you replace the compressor? Did it have an internal failure that pumped debris through the system? The condenser is the fist place to collect it.
Many times the condensers today do not lend themselves to 'flushing' because the interconnect passageways are so small that they can not be effectively 'flushed out'. Poor condenser efficiency would be contributing to your situation.
That being said, you said " '03 with 3.8 climate control".. but did not state the mileage.
Baron too has a good point. If your evaporator is all buggered up with pet hair or even a cabin air filter that has not been replaced in ''forever" that too would be effecting the efficiency.

Remember, an HVAC system does not create cold air rather, think about it as a bilge pump. HVAC simply removes heat from the inside to the outside. Pumps the heat overboard. And that heat pump is only as efficient as the flow and transfer of the heat at all points.

There may be an aggregate of minor loss at several points and not just one 'ah ha' thing that is going to give you the results that you are searching for.
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Still didn't get a chance to look at it last night,... and I'm busy all evening tonight and tomorrow night - Hockey season is just firing up for us and I have a band/music rehearsal tomorrow night... busy busy!

The compressor was replaced last summer due to it not coming on and/or a lack of performance - Ironically somewhat similar symptoms of which I'm experiencing now - only at that time it got to the point of not cooling at all. But it didn't blow up or anything as in start grinding and making noise or anything like that, so I think it shot a bunch of chunks and debris into the system - I've seen this happen in the past on other systems we've had - they call it "Black Death"
On one of those incidents with an 89 Cougar XR-7,. it shot crap into the evaporator and caused a blockage where the system could barely perform - I ended up holding the end of a socket extension against the outlet tube that I had in a 1/2 drive hammer drill that was set to "Hammer" only.. the intense vibration knocked the blockage loose and a dodged a bullet on that one! haha!

I've got 189,000 on this van,... and I've been pretty particular about keeping up with changing the cabin air filter - BUT I will try and get a peek at the evaporator.

I did try and have water spraying across the condenser coils while it was running one time, but didn't really notice a difference in temp change. Visually inspecting the coil from the front grill it look pretty good and clean (Unless the oil cooler is out in front?... couldn't really tell what's all in there.. (?)

I want to say it was a bit over filled when I first checked it (Or at least I thought it was.?) This was before I had the full set of gauges. I may try and put a shot in her real quick when I get home tonight and re-check the static pressures tomorrow morning early before I leave for work..

Thanks again for all of the support and suggestions on this problem!!
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Perhaps the condenser is internally full of crap and not working efficiently.
Our main goal here is to try and help others as much as we can.

I see your really like to help others, I usually like your responses but this time I think you are not 100% correct.

AC condenser doesn't gets internally "full of crap".

Condenser can only get externally damaged by a physical shock causing reduced internal refrigerant flow or leak or by "external" debris blocking air flow.

There are some "filters" in the system that will catch any impurity or humidity in the system. Even a catastrophic compressor failure wouldn't damage the condenser, some people recommend replacing a condenser after a compressor failure just to be on the safe side, but is not really necessary if you have the equipment to do a thorough cleaning and know how to use it.

I wouldn't spend money on a new condenser.

This is just my opinion.
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Ok a little update!...

I got home and put a shot or so of 134 in it... no change, checked the Clutch on the compressor and checked the Cabin air filter and Evap. coil...

Good news is:

1 - Compressor is ...compressing (Clutch is engaged)
2 - My Evaporator coil is clean as a whistle :D - filter was "ok"

.... as I pulled the cabin filter out I was blasted with HOT AIR out of the bottom filter access area/housing !!!!??!?! ... What the!?! .... Only thing I can think is that the blend door wasn't set up correctly?... but would that be hot air pumping through there... like is it drawing from the outside/engine area (I had just got home from St Louis and it was running in the driveway) ... or is the "Heat" on in the back ground or something...?

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there is a heater core the HVAC uses for heat, engine coolant runs through it and thats how you get "heat".

This van looks to be a bit different from other vehicles, looks like airflow goes from cowl intake to blower motor to filter then to evaporator. Then yes getting blasted with air sounds right. hot air though... something I'll have to take a look into. well if it was hot outside then yes you would get hot air... then airflow goes to evaporator core then maybe through heater core - depending on blend door position

if anything in the system was clogged, high and low pressures would be off, which is not your case

can you check the blend door next? thanks
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